1. Field of the Invention
The present invention relates to a jet, and more particularly, to a jet that can eject droplets of different sizes.
2. Description of the Prior Art
Currently, jets ejecting droplets of different sizes are widely applied to improve combustion efficiency of fuel engines or increase a selectivity of ink jet printing. For example, ink jet printers can print documents with droplets of different sizes, and therefore improve a color variability and a speed of printing.
Please refer to FIG. 1 of a schematic diagram of a jet 10 according to the prior art. The jet 10 is disclosed in U.S. Pat. No. 4,251,824 xe2x80x9cLiquid jet recording method with variable thermal viscosity modulationxe2x80x9d. The jet 10 uses a plurality of heat generating bodies 21xcx9c25 positioned on an axis of a chamber 12 to provide energy independently or in turn. Provision of energy causes a plurality of foams 31xcx9c35 to be generated in different positions, and therefore droplets of different sizes are ejected to print documents. However, since the plurality of heat generating bodies 21xcx9c25 must be disposed in one chamber 12 of the jet 10, the jet 10 must comprise more chambers 12 and heat generating bodies so as to improve the print quality. This gives rise to an increased difficulty in a fabricating process of the jet 10. In addition, the jet 10 has a disadvantage of easily jetting a satellite droplet, which leads to fuzziness in printed documents. The satellite droplets produced by the jet 10 follow the main droplets. When the jet 10 moves relative to the printed documents, the satellite droplets are printed onto places different from the main droplets. Thus, the print quality of the jet 10 is affected by the satellite droplets.
It is therefore a primary objective of the claimed invention to provide a jet which can eject droplets of different sizes to solve the above mentioned problem.
In a preferred embodiment, the claimed invention provides a jet, which uses a bubble as a virtual valve to increase flow resistance between a chamber and a manifold, or to interrupt flow communication between a chamber and a manifold. Then, another bubble is used to squeeze fluid inside the chamber and to eject the fluid out of the chamber. The jet comprises a substrate, an orifice layer, first nozzles and second nozzles. The orifice layer is positioned on the top layer of the substrate, and a plurality of first chambers and second chambers are formed between the orifice layer and the substrate.
It is an advantage of the claimed invention that the jet can eject droplets of different sizes by modifying sizes of the chambers and diameters of the orifices of the jet. Thus, the color variability and printing speed of the inkjet printer are improved.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.